S40 Oil Pressure Light and Sensor Issue

Sounds like my old S40 when the connection to the oil temperature sensor went bad. Check the cable and plug - could be a loose connection, or the cable might have rubbed through somewhere. It's a common problem. The sensor is used by the ECU to prevent situations of low oil and is located near the oil filter. Disconnect your battery before any interventions!

Thanks for the quick reply! Do you remember any specific areas to look for chafing or a bad connection? Any tips to confirm its location? I will disconnect my battery first.

I don't remember exactly – it was a while back. But jiggling the connector near the oil filter made the light flicker. I couldn't see the damaged cable myself. Your best bet is to swing by the workshop. They'll pinpoint the fault in no time.

You were spot on! I took it to my local independent mechanic. Turns out, it was a corroded connector, just like you suspected. 95€ later, all warning lights are gone. Thanks for steering me in the right direction!